Suction cleaner



July 20, 1954 e. A. BRACE SUCTION CLEANER Filed Sept. 1 1951 8 3 Q a m A m 8 'N .g

} ii I r0 cu \1 l ll Q l NH 9 :H u m 11 J I" mu 5 Sheets-Sheet 1 INVENTOR: GEORGE A. BRACE ATTORNEY July 20, 1954 BRACE 2,684,127

SUCTION CLEANER Filed Sept. 1 1951 3 Sheets-Sheet 2 m 9' LL. m I .1

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3 g a N INVENTOR. GEORGE A. BRACE Q ATTORNEY G. A. BRACE SUCTION CLEANER July 20, 1954 3 Sheets-Sheet 3 Filed Sept. 1 1951 INVENTOR. GEORGE A. BRACE BY ATTORNEY SUCTION CLEANER George A. Brace, Highland Park, 111., assignor to The Hoover Company, North Canton, Ohio, a

QFFICE corporation of Ohio Application September 1, 1951, Serial No. 244,794

22 Claims.

This invention. relates to suction cleaners and more particularly to a novel filter mounting and clamping assembly therefor having marked advantages over prior constructions.

lhe problem of providing a simple, efiective and easily operated means for mounting a disposable paper filter in a cleaner has been a most troublesome one. This is particularly true of tank type cleaners where it is desirable to employ a filter having an inlet opening of the same diameter as the body of the filter. Such filters require some type of internal clamp which extends into the filter opening and expands the walls outwardly to provide an air tight coupling between the filter and the cleaner casing. The tendency of the filter Walls to present an irregular and flimsy opening makes it diiiicult to insert the clamp without pushing the filter aside. Since the coupling operation, of necessity, occurs inside the cleaner casing it is impossible for the operator to observe whether a proper joint has been achieved with the result that the dirt is distributed throughout the cleaner and the motor-fan unit.

The object of the present invention is to provide a simplified filter mounting for a suction cleaner which entirely avoids the disadvantages of prior mountings. The construction makes use of an expanding clamp preferably carried by the filter chamber closure. The unique design of the clamp permits it to be collapsed to a much smaller diameter than its normal or filter clamping diameter. Hence, when collapsed, the clamp can be inserted into the filter mouth freely and without danger of displacing the filter. After the closure is closed, a single lever serves to operate the clamp and the locking mechanism for the closure.

Other objects of the invention include the provision of combined expanding type clamp and a resilient pilot for guiding the clamp into the open end of the filter wherein the pilot serves as a protective housing for the clamping mechanism.

Numerous other objects and advantages of my novel construction will become apparent from the following specification of two illustrative e1- bodiments taken in connection with the acconn panying drawings, in which:

Figure 1 is a side view of a tank cleaner inccrporating the invention with portions broken away to show structural details;

Figure 2 is a sectional view through the filter chamber closure and clamping device taken along line 2--2 on Figure 3;

.iii

Figure 3 is a sectional view along line 33 on Figure 2;

Figure 4 is a view similar to Figure 3 of a second embodiment of the invention; and

Figure 5 is a sectional view along line 55 on Figure i.

in the first embodiment, the open ended cylindrical casing it is supported on a pair of runners ii, I! and has a carrying handle l2 and a motor control switch [3 mounted on its upper side. The exhaust end is closed by a flattened end cap it having an air outlet in its central portion. The motor-fan unit it includes a conventional electric motor 16 and a multi-stage suction fan it having an axial air inlet opening it in its forward end. This unit may be supported in any suitable manner as by being nested in a soft rubber ring l9 and an annular ring having its periphery sealed to the casing wall. A. guard screen it covers the central opening in ring to prevent foreign matter from entering the fan. A pair of U-shaped guard wires 22, 22 arranged at right angles to one another are carried by ring 25 and serve to space the bottom of the filter from the guard screen so that air can fiow freely to the fan.

i'he right hand end of the casing provides a filter chamber in which one or more filter bags are located. As shown in Figure 1, the filter chamber contains an outer cloth filter bag and an inner paper filter bag 24 of substantially the same length. The filter chamber is normally closed by a cap generally designated by the numeral 25. This cap is pivotally connected to the lower side of casing it by hinge 26.

The details of the end cap and filter clamping device will be best understood by reference to Figures 2 and 3 from which it will be seen to comprise a cup-shaped outer member 2'! through which the air inlet tube 28 extends and an inner diaphragm 29 is connected between the rim of member and an intermediate portion of tube 23.

The filter clamp is mounted on diaphragm 29 and includes an endless spring wire coil to having e general appearance of a doughnut. The individual turns of the coil are spaced sufficiently to permit the coil to be collapsed readily to a much smaller diameter than its normal free diame er which is somewhat in excess of the di ameter of paper filter 24. The clamping coil is supported for free radial movement between diaphragm 2t and disk 3! which is seated about the inner end oi tube 28. A collar 32 is journaled about tube 28 between diaphragm 29 and disk 3|.

Extending from one side of collar 32 is a control lever 33 which carries a control handle 34 on its outer end so that collar 32 may be rotated by the operator for the purpose of collapsing filter clamp 30.

This is accomplished by means of a flexible wire cable 35 extending through the interior of spring 30, as clearly shown in Figure 2. The ends pass through eyelets 36 carried by adjacent turns of the coil. One end 31 of the cable is attached to a post 38 secured to disk 3i, while the other end 39 is attached to a post iil projecting downwardly from lever 33.

From the foregoing it will be apparent that when lever 36 is swung clockwise from the position shown in Figure 2, end 39 of the cable is pulled to the right with the result that coil 30 is contracted to a much smaller diameter. The amount of contraction can be readily controlled by the length or" the are through which lever 32 is swung. In practice it has been found that a 75 to 90 movement of the lever suiilces to reduce the diameter of the clamping coil by one and a half inches. This very substantial reduction in the diameter of the clamping coil not only releases the filter but provides more than ample clearance for the entry of the clamp into the inlet of a new filter bag. This is true even though the mouth of the bag is displaced to a considerable extent.

It is preferable to provide a rigid backing for the inlet of the filter back against which the clamp expands so as to grip the filter inlet between the backing and the clamp. This may be done by arrangement such as that illustrated in Figure 2. Thus, a channeled ring 32 is secured to the casing just inside the open end thereof having a seat as in its inner rim to support the soft rubber ring 44 on the inlet end of the cloth filter bag 23. Extending downwardly from seat i3 is a cylindrical flange 45 which terminates below the axis of clamping coil 39. It will therefore be evident that this flange provides a rigid circular wall against which the clamping ring 39 can press the rims of one or both filter bags.

The clamping device is preferably provided with a combined pilot and housing for the clamping device, as generally indicated at 46. This pilot is made of thin walled resilient material such as rubber or plastic and its lower inner end is secured to the rim of disk 3 i in any suitable manner as by riveting or cementing. Its upper end is similarly secured to diaphragm 29 and includes a ribbed thickened portion 3'! which cooperates with rim i l of the cloth filter to provide an air seal between the end cap and the cleaner casing. When the clamping coil St is collapsed, wall M flexes inwardly at the slightest pressure and pro vides a conical-like pilot which enters the paper filter and forces the walls thereof outwardly gradually as the end cap is pivoted toward closed position. Because of its very fiexible nature it gives readily when it encounters a non-circular or irregular portion of the filter and then expands the wall of the filter outwardly as the cap is moved into closed position.

The end cap is held in closed position by an arcuate latch detent member 58 one end of which is rigidly secured to ring 42. Control lever 33 can be engaged beneath the open end of this detent member only when the clamping coil is in its fully collapsed position and when the end cap 25 is in its closed position. Under these conditions, the control lever is located in the right hand end of slot 55 in diaphragm 29. The counterclockwise movement of the control lever allows the exposed end 39 of the cable to pass back into the clamping coil 30 as this coil expands under its own internal stresses to its filter clamping position shown in Figure 3. As the coil expands it forces wall outwardly against the wall or" the paper filter and eventually presses it directly against the wall of the cloth filter and against the backing wall iii. Under these conditions, the end cap is locked in its closed position and the filter is tightly clamped in place. If preferred, the under side of detent latch 58 may be notched so that lever springs into the notch to positively lock the lever in its closed position.

Operation Let us assume that it is desired to mount a flexible paper filter in the cleaner. This is most conveniently accomplished by upending the cleaner onto the flat end of cap H1. Handle 34 on lever 32 is then swung clockwise approximately until lever 33 passes beyond the end of detent 5B. As this lever is swung, end 35) of cable 35 is pulled to the right causing the clampi coil to be contracted inwardly towards the axis of the cleaner casing. As soon as the cover is unlatched, it may be pivoted upwardly entirely away from the open end of the casing.

A new paper filter is then inserted downwardly into the filter chamber so that its bottom rests on the bottom of the cloth filter. The operator passes her hand quickly around the rim of paper filter to assure that the walls lie near rose of the cloth filter. Closure 25 is then swung downwardly against the casing and control hair dle St is swung counterclockwise to its closed position thereby locking the cover in place. As the control lever is swung to the left, the tension on cable 35 is relaxed allowing the clamping spring to expand against the inner wall of the thin walled pilot member t8 and causing it to press no open end of the paper filter tightly against the wall of the cloth filter and rigid backing member 3-5.

The usual flexible hose and cleaning tools are then connected to tube 25; as the cleaner is returned to its operating position on runners ii. After the cleaner has been in use for a suflicient period to fill the filter bag with dirt, the operator disconnects the hose and upends the cleaner onto cap M. The removal of the dirt filled bag i accomplished quickly and very simply by rotating control handle 3 clockwise to unlatch the end cap and simultaneously collapse the clamping ring. Not until the clamping ring is fully collapsed is it possible to swing the end cap to its open position. The top of the filter bag is then lifted from the casing and carried to a point of disposal. A new bag is inserted by following the simple procedure described above.

It will be at once apparent that the cleaner may he used with the cloth filter alone, the paper filter alone, or with the two filters nested to gether. If the cloth filter is not desired it is simply removed from the cleaner. In this case the paper bag is inserted until its bottom rests on guard wires 22, 22 and its top is sealed against backing ring is by the clamping device in the same manner described above. The expanding capacity of the clamping ring readily adapts itself to the slight additional requirements and is adequate to press the top of the paper filter tightly against the wall of ring t5.

If on the other hand the operator discovers that her supply of paper filters is temporarily exhausted, she may use the cleaner with the cloth filter alone and without performing any different or additional operation than described above.

A second embodiment of the invention is illus trated in Figures 4 and 5. The same or similar elements are indicated by the same reference characters used in describing the first embodiment except that they are distinguished by a prime.

As will be readily observed, the second embodiment is generally similar to the first except for the construction of the clamping ring. The alternate clamping device comprises a soft rubber ring 60 generally rectangular in cross section. This ring is mounted between a lower ring 3! and an upper ring member 29'. Embedded in the inner wall of the clamping ring are a plurality of cords 65 the outer ends of which are attached to hooks 62 carried on the side wall of collar 32'. The intermediate portions of cords 6! pass over rollers 33 carried by pins 64 secured to ring 3!. In its normal relaxed position, clamping ring 60 is circular and has a diameter somewhat in excess of the diameter of the filter inlet. Accordingly, it will be understood that in its expanded normal condition, the ribbed outer wall of the ring engages the inner wall of the paper filter and holds it pressed tightly against the side wall of cloth filter 24' or against the wall of the backup ring 45'. However, when collar 32' is rotated, cords 6| are pulled inwardly to collapse diametrically opposed portions of ring 69 to greatly reduce the diameter of all portions of the ring.

Operatic n Operation of the second embodiment is generally similar to that of the first embodiment, as will be readily apparent from the foregoing description of the structure. Let us assume that the cleaner is. assembled as illustrated in Figure 4 and that the filter bag is full of dirt. To replace it with a fresh filter, the operator up-ends the cleaner onto the rear end cap and rotates, control lever 34 clockwise until it passes beyond the open end of latching detent 48. This movement of the lever causes the hook supported ends of cords 6! to be rotated in a direction to pull diametrically opposed portions of the clamping ring radially inward to collapse the ring to the position indicated in Figure 5. l'fhis not only unlatches the end cap, but releases the filter. The end cap may now be swung to open position about hinge 26' so that the dirty filter bag can be withdrawn and carried to a point of disposal.

A new filter bag is then opened and inserted so that its bottom rests on the bottom of cloth filter 2d. The end cap is lowered and handle 34' is swung counterclockwise simultaneously tolock the cover closed and to relax the tension on cords 6! so that clamp fill expands outwardly to clamp the filter tightly against the wall of the cloth filter and against backing ring 45. Obviously, the second embodiment may be used with the cloth filter alone, with the paper filter alone, or with both filters in the same manner as described in connection with the first embodiment.

It will be readily apparent from the foregoing that my self-expanding clamping device constitutes an effective means for releasably securing the cover in place on the cleaner casing due to the large area frictional contact between the clamp and the inner wall of the cleaner casing. Latching detents 48 or 48' then serve primarily as a means for requiring the operator to move having control lever 34 or 34 a predetermined distance to assure the desired contraction of the clamping ring before it is possible to remove the cover.

While the drawings do not illustrate any means for retaining the control lever in the open position thereof, it will be understood that a simple spring latch or its equivalent can be attached to the inner wall of cover 2! for locking lever 33 or 33 against return to its normal position until the operator releases the spring latch.

While I have shown but two embodiments of my invention it is to be understood that these embodiments are to be taken as illustrative only and not in a limiting sense. I do not wish to be limited to the particular structure sho-wnand described but to include all equivalent variations thereof except as limited by the scope of the claims.

I claim:

1. A suction cleaner having a casing provided with a filter bag opening, said casing being adapted to house an open end filter bag having a mouth substantially co-extensive with said casing opening, a removable cover for said opening, an expanding filter clamping means on the inner wall of said cover adapted when contracted to telescope into the mouth of a filter bag and to expand radially to a substantially larger diameter against the inner rim thereof to hold the same in place in said cleaner, said clamp being contractable so as to enter said filter mouth easily and without displacing the same inwardly into said casing, and common manually operable means for operating said clamping means to expand the same radially against the inner rim of said filter bag mouth and for releasably holding said cover in place over saidcasing opening.

2. A suction cleaner as defined in claim 1 wherein said clamping means comprises a selfexpanding clamp arranged to expand against the inner walls of a filter bag in an air tight manner when released and wherein said manually operable means is operable to contract said clamp to a. substantially smaller diameter to release the filter bag.

3. A suction cleaner casing having a large area opening to receive a filter bag and having an inturned flange about said opening against which the mouth of a filter bag positioned in said oasing may be seated, a cover for said opening, a self-expanding filter clamp on the inner wall of said cover adapted when contracted inwardly toward the axis thereof to telescope freely into the mouth of a filter bag positioned in casing and when released to expand automatically to clamp the mouth of a filter tightly against said inturned flange, and manually operable means accessible from the exterior of said casing for contracting said clamping means while said cover is being assembled over said casing opening and for thereafter releasing the same so that it can expand against the filter mouth.

4. In combination, a casing for a filter bag a large area opening, said casing being adapted to house a filter bag having an inlet mouth of substantially the same area as said casing opening and to have the outer rim edge of said mouth seated against the rim of said opening in an air-tight manner, a cover for said opening, a combined pilot and expanding clamp for said filter mounted on the inner wall of said cover, said combined pilot and expanding clamp being flexible and contractable from a normal filter clamping diameter to a substantially smaller diameter whereby said pilot and clamp can be freely telescoped into the open mouth of a filter bag housed within said casing as said cover is seated over said opening, said clamp having a normal free diameter in excess of the diameter of the filter mouth so as to expand automatically against the walls of the filter when not restrained, and means connected with said clamping means for forcibly contracting the same from said normal diameter to a smaller diameter to release the filter and permit removal of said cover from said opening.

5. The combination defined in claim a includ ing means for pivotally connecting one side of said cover to said casing and for permitting said cover to be swung from closed position to an open position in which it does not interfere with the axial withdrawal of a filter bag through said casing opening, said pivotal connection being operable to guide said combined pilot and clamping means into the open mouth of a filter bag as said cover is swung to closed position.

6. The combination defined in claim 4 wherein said means for contracting said clamping means includes means carried by said casing requiring the operation of said contracting means through a path of predetermined length before said cover is free for removal from said opening.

'7. A filter clamping device of the self-expanding type comprising, a filter chamber having a wide area opening, a cover member for said opening, said filter chamber being adapted to enclose and support a wide mouth filter bag so that the mouth thereof is closely adjacent the rim of said wide area opening, a tubular member extending through said cover, a resilient clamping ring surrounding and spaced radially outward from the inner end of said tubular member, said clamping ring having a normal unrestrained diameter in excess of that of the mouth of a filter bag adapted to be received by said chamber, and means for contracting said clamping ring radially inwardly to an efiective diameter appreciably less than the mouth of a filter so that said cover and clamping ring can be readily inserted into and withdrawn from the mouth of the filter, said last named means also being operable to release said clamping ring when it is in place in said chamber so that said ring is free to expand against the inner wall of a filter mouth and hold the same in air-tight engagement with the inner wall of said chamber.

8. A filter clamping device as defined in claim '7 wherein said clamping ring comprises a resilient coiled member having its ends connected together to form a ring.

9. A filter clamping device as defined in claim 8 wherein said contracting means for said coiled ring includes means for collapsing the turns of said coil toward one another in opposition to the tendency of the same to remain in their normal spaced position whereby the diameter of said ring is reduced.

10. A. self-expanding clamp comprising, spaced parallel plates, a resilient ringlike member supported between said plates having a normal unrestrained diameter in excess of the diameter of one of said plates, control means movably supported in part by said plates and connected to the inner side of said ring, said control means being operable to move at least portions of said ring inwardly toward the center thereof to reduce the over-all effect diameter thereof appreciably and being movable to another position in which said ring is free to expand to a larger diameter under its own inherent resiliency.

11. A self -expanding clamping device as defined in claim 10 wherein said resilient ring-like memher is a solid homogeneous member having one end of a plurality of flexible tie members secured to its inner wall at circumferentially spaced points, the other end of said ties being connected to said control means, and stationary means on one of said plates beside each of said ties whereby movement of said control means in one direction pulls spaced portions of said ring member radially inward to reduce the effective diameter thereof.

12. A self-expanding clamping device as defined in claim 11 wherein said control means includes a lever rotatably supported by said plates and to which said other ends of said ties are attached.

13. A self-expanding clamping device as defined in claim 11 wherein the outermost wall of said resilient ring-like member is provided with at least one annular channel forming a pair of annular flexible ridges for more efiicient sealing engagement with a surrounding wall when said clamp is in its expanded position.

14. A self-expanding clamping device as defined in claim 10 wherein said resilient ring-like member comprises a spiral wire coil having its ends inter-connected to form a torus.

15. A self-expanding clamping device as defined in claim 14 including a flexible tension member extending around the interior thereof and having its ends projecting through the inner wall thereof, means for anchoring one of said ends, and means connecting the other of said ends to said control means whereby movement thereof in one direction tensions said stringdilze member to contract said resilient ring and reduce its diameter.

16. A self-expanding clamp as defined in claim 10 including a flexible covering for said resilient ring-like member, said covering having its lateral edges connected to said plate members so as to enclose said clamping ring.

17. In combination, a self-expanding clamp comprising, an outer open ended tubular casing having a seating area on the inner rim of said opening, a flexible walled inner tubular member adapted to be housed therewithin and to have the rim thereof expanded outwardly into contact against the seating area on the rim of said casing opening, spaced parallel disks the outer one of which is adapted to provide a closure for said casing opening and the inner one of which is adapted to be located within said casing, a resilient clamping ring supported between said spaced disks having a normal unrestrained di-- ameter in excess of the diameter of said seating area on the rim of said casing opening, control means for contracting said clamping ring to reduce the diameter thereof substantially so that it can be moved freely into and out of said casing opening and the end of said inner flexible walled tubular member and for releasing said. clamping ring for expansion against the inner rim of the inner tubular member and forcing the same outwardly into air-tight contact with the seating area on the rim of easing opening.

18. In combination, an outer tubular member, a thin flexible walled inner tubular member having a rim adapted to be supported opposite a seating and clamping area therefor adjacent the inlet end of the outer member, a combined clamp and closure for said tubular members comprising a large diameter outer wall and an inner wall parallel thereto having a diameter appreciably smaller than the end of said inner tubular member so as to be readily telescoped thereinto, a resilient ring-like clamping member supported between said walls having a normal unrestrained diameter in excess of the diameter of the seating and clamping area on said outer tubular memher, and control means operable to contract said clamping member to a much smaller diameter while it is being telescoped into the ends of tubular members and for thereafter releasing said clamp so that the same expand under its own inherent resiliency to seat the rim of the inner tubular member firmly against the seating area therefor on said outer tubular member.

19. The combination defined in claim 18 including means for locking said closure in place across the end of said tubular members, and a common manual operator for releasing said closure locking means and for contracting said ringlike clamping member.

20. The combination defined in claim 19 including mean pivotally connecting one edge of said closure to the end of said outer tubular member whereby the same can be swung toward and away from the ends of said tubular members when said locking means and said clamping means are released.

21. The combination defined in claim 18 wherein said inner tubular member is formed of air pervious paper and wherein said combined closure and clamp includes means providing an air inlet passage extending through the inner and outer walls thereof.

22. In combination, an open ended suction cleaner casing for housing a filter bag having an inlet opening adapted to be seated and clamped to the inner rim thereof, a combined closure and clamp for said openings comprising a cover member, a tubular inlet extending therethrough, a resilient ring-like clamping means surrounding said tubular inlet on the inner side of said cover and having a normal unrestrained diameter in excess of the diameter of the rim of said casing opening for contacting the inner wall of the filter bag inlet opening seating the same firmly against said casing rim, said clamping means being carried by said cover and being operable to frictionally engage said casing rim to hold the same closed when expanded thereagainst, and common manually operable control means accessible from the exterior of said casing for simultaneously contracting said clamping means to release said cover so that it can be moved away from said opening and to release said filter bag so that it can be withdrawn from said casing through said opening.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,319,079 Hoover Oct. 21, 1919 1,829,255 Ballou Oct. 27, 1931 1,847,352 McClatchie Mar. 1, 1932 2,159,116 Zacharias May 23, 1939 2,193,778 Rabaten Mar. 12, 1940 2,447,500 French Aug. 24, 1943 2,467,503 Scriven Apr. 19, 1949 FOREIGN PATENTS Number Country Date 387,245 Great Britain Feb. 2, 1933 449,288 Great Britain June 24, 1936 

